This invention relates to a positive electrified charge control agent which is used for a positive electrified toner for developing an electrostatic image or a powder paint, a positive electrified toner for developing an electrostatic image including the agent, and a charge control method of the toner.
Electro photography applied to a copy machine, printer or facsimile performs to develop an electrostatic latent image on a photosensitive frame with toner having frictional electrification and then the imaged toner is transferred and fixed to copy or print onto paper.
The electrification property of the toner is an important factor to raise a development speed of electro photography and form the vivid image. Therefore, a charge control agent is added to the toner so as to control a proper quantity of the electrification stably and quicken a rise speed of the electrification. The charge control agent is for positive or negative electrification. For instance, as the positive electrified charge control agent, it is disclosed in Japanese Patent Provisional Publication Nos. 63-206768 and 62-62369. As the negative electrified charge control agent, it is disclosed in Japanese Patent Provisional Publication No. 3-276166. The charge control agents disclosed in those publications are organic metal complex compounds which organic ligands are coordinated to a central atom of metal such as aluminum, tin, lead, cobalt, iron, nickel, zinc, chromium, copper, barium, and beryllium. While the charge control agent for negative electrification disclosed in Japanese Patent Provisional Publication No. 4-293057 is compound which organic ligands are coordinated to organic ligand to a central atom of silicon. Therefore, the toner including this charge control agent for negative electrification is a negative electrified toner. The toner is used for developing a positive electrified electrostatic latent image on a photosensitive frame.
It is required that the toner has more excellent electrification property and stability than a prior toner to achieve high speed and high definition in copying and printing. Furthermore, it is required that the toner and the charge control agent included therein have preservation stability and environmental hygiene on the latest trend.
Moreover, it is required that the charge control agent is able to be used of a powder paint for a electrostatic powder paint method which attracts and bakes the electrified powder paint onto a surface of a frame work having charge, and has the proper electrification property and stability.